A method of configuring a communication channel prior to the transmission of an input signal along the communication channel, the communication channel comprising a plurality of sub-channels, the method comprising determining the strength of the input signal and in accordance with the determined signal strength, selecting a set of the plurality of sub-channels and transmitting said input signal along the set of sub-channels in parallel, wherein each of the sub-channels has a predetermined noise characteristic such that the set of selected sub-channels exhibits a combined noise characteristic in which the standard deviation of the noise is proportional to the signal strength.